Live in the present moment

When you are focused on the present moment, your mind thinks clearly. Is not distracted by unnecessary things like opinions, judgements, fears.

Instructions

Find the method to pull you into the present moment.
It can be exercising, unplugging, walking in the park, meditation. A good method is to observe animals - they are a constant reminder of how pleasant the present is.
Catch your mind when it goes astray.
Discard distracting thoughts. Leave them alone. Focus on the present and what is important.
Focus on situations as they are.
Ignore what they represent, mean, or why they happened.